1. Field of the Invention
The present invention relates to an electrochromic device having the functionality of a secondary battery and a method for manufacturing the device. More particularly, the present invention relates to an electrochromic device in which a double metal oxide layer including mesoporous metal oxide particles and macroporous metal oxide particles is disposed on a transparent electrode to provide improved contrast to the device, and a cathode active material for a lithium secondary battery is disposed on a counter electrode to allow the device to function as a lithium secondary battery.
2. Description of the Related Art
Electrochromic devices are devices whose constituent materials are stimulated by external stimuli to cause chemical or physical changes in molecular structure and induce visual electrochromic effects. When an external electrical stimulus is applied to a transparent electrode and a counter electrode between which an electrolyte is filled to create a potential difference between the electrodes, ions and electrons contained in the electrolyte migrate into an electrochromic layer to participate in a redox reaction, thus causing visual changes in color or shade. Electrochromic devices are currently used in information processing, including recording, display and output of information, because of their ability to control optical properties.
Current electrochromic devices suffer from low contrast and/or long response times. There accordingly remains a need in the art for improved electrochromic devices.